Process for catalytic hydrogenation of hydrocarbon oil and the like



March 6, 1934. VP, L, ET AL 1,949,630

PROCES S FOR CATALYTIC HYDROGENATION OF HYDROCAR BON OIL AND THE LIKE Filed June 25, 1929 mad-M NYENTORS{ ATTORNEY WWW Patented Mar. 6, 1934 PATENT OFFICE PROCESS- FDR, CATALYTIC HYDROGENA- TION OF HYDROCARBON OIL AND THE LIKE Robert P. Russell and Willard C. Asbury, Baton Rouge, La., assignors P y to Standard-I. G. Com- Application June 25, 1929, Serial No. 373,501

' 6 Claims.

The present invention relates to an improved process for obtaining valuable products from carbonaceous materials and more specifically comprises an improved process for the hydrogenation of hydrocarbon materials, more especially petroleum oils and the like. The method will be fully understood from the following description and the drawing.

The drawing is a semi-diagrammatic view in sectional elevation of an apparatus constructed according to one form of the invention and indicates the fiow of materials.

Referring to the drawing, reference numeral 1 denotes a fired coil arranged in a furnace setting '2 of any suitable form. The coil discharges by line 3' into a drum 3 which is the first of a series of drums of which only 3 and 4 are shown. These drums are adapted to withstand high pressure, for example, 200 atmospheres or higher at elezo vated temperaturesin excess of about 700 F. and also to withstand the corrosive effect of oil and gas rich in hydrogen. internally by electrical heaters (not shown) or by other suitable means but it has generally been found suitable to heavily lag the drum by an insulating layer 5 and to operate without addition of heat to the drum or drums.

The main supply of oil is discharged into the base of drum 3 from which it is withdrawn by means of line '6, fitted with a regulating valve 7,

'and forced into the lower part of the second drum 4. A minor supply of fresh oil may also be sent directly into drum 4; by line 4a. The liquid level in drum 3 is preferably maintained somewhat higher than that in the succeeding drum 4 so that the difference in head will cause fiow from drum 3 to drum 4. A withdrawal pipe 8 is provided for drum 4 and it is connected into a manifold 9 from which oil is withdrawn by pipe 10 to hot oil pump 11. This pump may be of any preferred design, such as a liquid piston or surge pump, and discharges to theiheating coil 1 described above. Valvedpipes 12 .and 13 are provided'for withdrawing oil from the lower portions 'of drums into the manifold 9.

Hydrogen or a gas rich in free hydrogen is supplied to the inlet of coil 1 by a pipe 14 and this is preferably the only source of hydrogen to drums 3 and 4, but if desired additional relatively pure hydrogen may he -added to the lower parts of the drums by line 15 and branch pipes 16 and 17 for that purpose.

A manifolded vapor line 18 is provided to remove vapor from the tops of drums 3 and 4 but if desired valve 18a may be closed and vapor will The drums may be heated" be removed only from the last or latter drum or drums of the series. Vapor is conducted to suitable overhead equipment which is adapted to the particular needs of the process, depending on its method of operation, as will be described, but for illustrative purposes the separation equipment most suitable when the process is used to produce a maximum yield of light oil, such as is suitable for motor fuel, will be described. Vapor line 18 connects to a plate tower 19 which is fitted with cooling coil 20 at the top and a vapor line 2l connected to a condenser 22. Condensate is emptied intoa gas separator 23 from which distillate is removed to storage (not shown) by line '24. Gas is taken from the top of the separator to a purifier 25-which is adapted to remove a part of the hydrocarbon constituent of the gas along with hydrogen sulphide and may comprise a high pressure oil scrubbing system, although other suitable means may be employed. Purified gas is compressed by booster 26 and fresh or make-up hydrogen may be added by line 27. Compressed gas then passes by line 28, is preheated in coil 20, and feeds lines 14 and 15, i-described below.

Fresh oil is forced through pipe 29 by feed pump 30 and may be passed directly into recirculation pipe 10 by means of line 31, or if desired a part may be forced into, the upper part'of tower 19 by pipe 32 and'a' pipe 33 is provided to take reflux and feed from the base of tower 19 to line 31. A pump may be placed in line 33 or the tower may be sufilciently raised to cause flow by gravity, as wilLbe understood.

In the operation of my process, a single drum or a series of drums may be provided to maintain a body of oil under hydrogenation conditions. The temperature is maintained within the range from about 700 to 950 F. and a hydrogen pressure of at least 20 atmospheres, and preferably about 200 atmospheres is maintained. A catalyst is held in suspension in the oil to promote the reaction. A great variety of catalytic materials may be used but in general oxides of chromium and molybdenum and their mixtures, or mixtures of these with other oxides or salts of other polyvalent metals, are preferred. These substances are in general of a density considerably greater than the oil and ordinarily settle rapidly from suspension, even though in finely divided form, for example, capable of completely passing a 200 mesh screen. The settled catalyst packs down and the individual particles become bonded together by the heavy tarry materials in the oil so as to plug up flow lines and necessitate shut-downs at relatively short intervals. 7

The present invention contemplates feeding the drum or drums at the lower ends and maintaining an upward flow sufiicient to substantially prevent catalyst settling and it is preferable to maintain the flow in excess of the free settling rate of the catalyst. In this way the suspension is kept substantially uniform in the drum and although the critical rate is somewhat different for different catalysts and oils, it has been found that a rate of 200 ft. per hour, calculated from the volume of oil above and the cross-section of the drum, is satisfactory, for example, with a catalyst passing a 200 mesh screen and 30% passing 325 mesh screen, having a density of pounds per cu. ft. where the oil is about 15 A. P. I. and drum temperature is 860 F. average.

The preferred method of operating the drum is to feed at the bottom and hold a level to full by withdrawing oil from an elevated point of the drum. It has been found. however, to be most satisfactory to withdraw the major quantity of oil from an elevated point and a minor quantity from the base since this tends to give the most uniform distribution of catalyst. It is also, as stated above, preferable to maintain a rate of flow greater than the free settling rate, but sometimes with extremely'heavy or very coarse catalysts this is not feasible or desirable and it is particularly advantageous to withdraw a part of theoil from the base of the drum, especially when the feedis not introduced at the lowest point of the drum.

Vapor may be withdrawn from each drum or from certain of the drums, as will be understood. If vapor is withdrawn only from't-he last, all of the hydrogen may be introduced by means of coil 1, but if vapor is withdrawn from other drums. it is particularly advantageous to add additional hydrogen by pipes 16 and 17. The rate of flow in the individual drums may be regulated to the desired value by addition of a small quantity of oil directly from the heating coil to compensate for that vaporized and/or withdrawn from the lower parts of the various drums.

The present method may be used, as described above, to produce large yields of low boiling oil suitable for motor fuel, and in such case the temperature is generally above 800 F. but the process may also be used to improve the quality of heavy lubricating and other light or heavy oils and for this purpose lower temperatures, say between 700 and 800 F., are most suitable. Where it is desirable to make lubricating oils, the separation equipment beyond the drums is preferably in the form of a flash tower which may be held at reduced pressure as disclosed in Ser. No. 379,914 filed July 22, 1929 by P. L. Young.

The present invention is not limited to the use of petroleum or heavy cuts therefrom, and tars. shale oils and the like or solid carbonaceous material such as coal tpreferably after removal of mineral matter) may be used. The process is not to be limited to any theory.

We claim:

1. In a process for obtaining valuable products from hydrocarbon oil by subjecting the oil in liquid phase to an elevated temperature in the presence of a finely divided catalyst, an improved process for maintaining catalytic material in suspension in the oil, and at the same time maintaining the suspension at reaction conditions for an adequate length of time, which comprises flowing said suspension upwardly through a primary reaction zone at a. velocity which is sulficient to prevent the solid material from settling, continuously withdrawing oily suspension from the upper part of said reaction zone and causing it to flow into the lower end of a second reaction zone maintained under the same conditions as the primary reaction zone, removing vapor from the said second reaction zone, and returning the remaining oily suspension through a heat ing zone to the first reaction zone.

2. In a process for obtaining valuable products from hydrocarbon oil by hydrogenation at temperatures between 700 and 950 F., under pressure in excess of 20 atmospheres and in the presence of finely-divided particles of catalytic material, the improved method of maintaining the catalytic material in suspension in the oil and at the same time providing for a sufficient time of reaction, which comprises causing the suspension to flow upwardly through each of a plurality of hydrogenation zones connected in series at a rate in excess of the settling rate ofthe particles of catalytic material.

3. Process according to claim 2 in which the vapor is removed from each of the hydrogenation zones.

4. Process according to claim 2 in which the total reaction product consisting of gas, vapor and liquid containing catalyst are conducted from the top of each hydrogenation zone to the base of the succeeding zone.

5. Process according to claim 2 in which a portion carrying vapor and gas is separately withdrawn from the top of each hydrogenation zone, and only the liquid reaction product including catalyst is conducted to the succeeding zones.

6. Process according to claim 2 in which the distillate is withdrawn from each hydrogenation zone and fresh oil is added directly to each of 1 such zones.

' ROBERT P. RUSSELL. WILLARD C. ASBURY. 

